Percussion-tool.



W. B. SULLIVAN.

PERCUSSION-TOOL.

APPLICATION FILED MAYII. 191a.

,296, 38 Patenfed Mar. 4, 1919.

ITnferTrF Q/wzbm SuZZzi/an 1? which are operated by The object of dent of Chicago,

of which the following is a specification, which are illustrated in the accompanying "be repeatedly use ,either upon i E El PERCUSSION-TOOL.

To all whom it may concern:

Be it known that I, WILLIAM B. SULLI- VAN, a citizen of the United States, and resi county of Cook, and State of Illinois, have invented certain new and useful Improvements in, Percussion-Toolsl, an

drawings, forming a part thereof.

The invention relates to punches, rivet sets and the like, and especially to those tools being driven with great. force'against the work and which may heated and cooled in service as by intermittent usefiupon a heated objective. the invention is to provide a efficiency and durability for hot or cold work, and'of such a character that skilful heat treatment is not required for obtaining the most desirable condition of the tool, as to hardness.

The single figure of the accompanying drawing shows a rivet set designed for use with so-called air hammers and which it is proposed should embody the present invention, apart of the tool being shownin sec tion. 1

The service to which tools, as 10, are subjected makes it desirable that they should have the required degree and character of hardness to perform the operations for which they are intended and at the same time afiord great resistance against wear, either by abrasion or at the head 11 and shank 12. In order that tool of great the tool may be used upon both heated and.

cold objectives it is also required that it should have great longitudinal and transverse strength in the required hardness state and that all of .these properties should be retained at the highest temperatureswhich may be attained inany part of the tool in That is to say,

service, as also after subsequent cooling. the tool .should have high red hardness and be free from air hardening properties. Abrasion or distortion of the tool when the head, as 11, is driven against a heated objective and brittleness due' to excessive hardness, after repeated use, are thus avoided. The strength'and'hardness.

required for cold operations is thereby retained even after long continued service.

. It is accordingly proposed that theim-,-

proved tool, as 10, should have a fixed metalloptric structure to a hightemperature and should be capable of being quenched in I Specification of Letters Patent. Application filed May 11, 1918. Serial No. 233,942.

high proportion of s1 distortion, particularly bility of the 'tool"'n, A are obtained.

, Patented Mar. 4, 1919.

- p r either oil or water from any higher temperature throughout a wide range without producing excessive hardness. For this purpose the invention contemplates a tool formed from steel com rising an unusually icon. It has been found that remarkable results are obtained with tools formed from steel having the following composition Silicon 1. 75-to 2'. 25% Manganese r- ..50 to 1.00% Carbon .50 to .65%

Such a tool may be made from open hearth steel and it will be of substantially the same hardness if quenched in either oil 1500 and 1900' F. s

The relatively large proportion of silicon is believed to render the metalloptric state or condition of the tool obtained by quenching, stable to any temperature likely to be attained in any part of the tool in use upon hot work without imparting the air hardening properties which would cause the tool to become excessively hard and brittle in service. Furthermore, the wide iange of temperatures from which the tool may be quenched with substantially uniform results renders skilful treatment unnecessary while the hardness and strength are suflicient to permit longcontinued use in any punching operation without fracture orchange of size or form beyond the usual limits of tolerance.

The invention accordingly provides an inexpensive tool strength for any piercing or punching operation upon either hot or cold work and most extraordinary results with respect to duralong continued service While reheating the tool, as 10, after quenching to any temperature which does not closely approximate 900 F. does not materially change its hardnessffor the purpose of relieving internal strains'it may-be desirable-to bring the tool to a uniform temperature of about-600 F.,- after quenching, particularly if-the tool is of irregular shape, as sl'i'o wn." It will beunderstood that the essential hardness required for the particularclas's'pf tools indicated is determined by their composition. That. is to say, substantially the same hardness is obtained by quenching from any temperature a ove 1500 F. through a wide-range, and this of the required hardness and.

.or water from any temperature between hardness is not modified by reheating to lower temperatures. The improved tool is thus distinguished from tools of so-called straight carbon steel wherein the hardness obtained is determined by the temperature to which the tool is reheated after quenchlng.

The improved tool is also distinguished from tools of any of the alloy steels by being free from air hardening properties. These distinctions are believed to be due to differences in the character of the martensite produced by quenching the difierent tools from temperatures above the decalescent points of the corresponding steels. That of the so-called straight carbon steel tools is hard and brittle but rapidly decomposes when the tool is reheated after quenching. On the other hand, that of the alloy steels is originally hard and strong, retains its hardness and strength to high temperatures but increases in hardness and becomes brittle upon subsequent cooling in the air. The martensite produced by quenching the tool provided by the present invention difiers from both in being stable up to temperatures at which the hardness obtained in socalled straight carbon steels by quenching would be substantially destroyed and airhardening steels would be materially modified. The tool is described in the accompanying claims as comprising an impactreceiving shank and a punch head with a view to indicating that it is specially formed for engagement with the objective and to provide a place where it maybe struck to afford the impulse by which the work is performed, but this expression 'is not intended to indicate that the head and shank are necessarily of different dimensions, as

shown.

I claim as my invention-- punch head composed of steel containing approximately two per cent. silicon.

2. A percussion tool for punching, rivet setting, and like hot or cold operations, comprising an impact receiving shank and a punch head composed of steel containing approximately two per cent. silicon, manganese in appreciable quantity not substantially exceeding one per cent., and approximately one-half per cent. carbon.

3. A percussion tool for punching, rivet setting, and like hot or cold operations, comprising an impact, receiving shank and a punch head composed of steel containing one and three-quarters to two and onequarter per cent. silicon, one-half to one per cent. manganese, and one-half to sixty-five one-hundredths per cent. carbon.

4. A percussion tool for punching, rivet setting, and like hot or cold operations, comprising an impact receiving shank and a punch head composed of steel containing iron as its principal ingredient and silicon largely in excess of any ingredient other than iron, the amount of the silicon content being approximately two per cent.

5. A percussion tool for punching, rivet setting, and like hot or cold operations, comprising an impact receiving shank and a punch head composed of steel consisting of iron as its principal ingredient combined with another substance having the property of .siliconin imparting to the steel, when approximately two per cent. is used therein, the quality of red hardness without air- .hardening properties.

6. A percussion tool for punching, rivet setting, and like hot or cold operations, comprising .an impact receiving shank and a punch head composed of steel having,.after quenching, the red hardness characteristic of self-hardening steels without the property of air hardening.

WILLIAM B. SULLIVAN. 

